In a transport machine such as an automobile, in order to achieve weight reduction, the rate of usage of synthetic resin members has increased. For example, in Patent Document 1, a vehicle body structure where a synthetic resin member is positively used for a portion which does not substantially contribute as a strengthening member, and where the synthetic resin member is joined to a metal member with adhesive agent, is disclosed.    Patent Document 1: Japanese Patent Application Laid-open No. H09-86445